Meat Processing Equipment Having Improved Yieldable Arresting Means

ABSTRACT

Meat processing equipment is disclosed that includes a first element having a first face; a second element having a second face. The first and second faces extend parallel to one another and define a common plane between the first and second faces. The first and second elements are relatively movable with respect to one another. Yieldable arresting features are included for yieldably arresting the first and second elements in at least one predetermined position of relative movement, the yieldable arresting features include cooperating first and second permanent magnets, associated with at least one of the first and second elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 13/804,215filed on Mar. 14, 2013 which is a continuation of PCT/NL2011/050716,filed Oct. 2011, which claims the benefit of Netherlands Application No.NL2006075, filed Jan. 26, 2011, each of which is hereby incorporated byreference herein in its entirety.

TECHNICAL FIELD

The invention relates generally to meat processing equipment, inparticular automated meat processing equipment having improved yieldablearresting means.

BACKGROUND

Yieldable arresting or indexing arrangements are fairly common inautomated meat processing equipment. One well known application is inrotatable carcass hangers for poultry processing conveyors and examplesare described in EP 0444782, EP 0786208, and U.S. Pat. No. 5,092,815.All of these known arresting means rely on ball detents that are biasedinto recesses by the force of a helical spring. The necessary springsand cavities to house these present a serious hazard of bacterialcontamination, which is objectionable in the meat processing industry.Although regular cleaning of the equipment is aimed at minimizing thehazard of bacterial infection, the risk itself could not effectively beeliminated with the known yieldable arresting means. Apart fromrotatable carcass hangers, yieldable arresting means can also findapplication in various other parts of meat processing equipment,including bone holders.

Accordingly it is an aspect of the present invention to propose animproved yieldable arresting means for arresting relatively movableelements of meat processing equipment in at least one predeterminedposition of relative movement. In a more general sense it is an aspectof the present invention to at least overcome or ameliorate one or moreof the disadvantages of the prior art. It is also an aspect of thepresent invention to at least provide alternative structures which areless cumbersome in manufacture and use and which can be made and usedrelatively inexpensively. At any rate the present invention is at thevery least aimed at offering a useful choice and contribution to theexisting art.

SUMMARY

The present invention provides a meat processing equipment including: afirst element having a first face; a second element having a secondface; wherein the first and second faces extend parallel to one anotherand define a common plane between the first and second faces; the firstand second elements being relatively movable with respect to oneanother; and yieldable arresting means for yieldably arresting the firstand second element in at least one predetermined position of relativemovement, wherein the yieldable arresting means include cooperatingfirst and second permanent magnets, associated with at least one of thefirst and second elements. This arrangement eliminates the need forhelical springs and open cavities and thus ensures more hygienicconditions than were possible with the prior art.

Advantageously in a meat processing equipment according to the inventionthe first and second magnets can be either attracting or repelling oneanother. Both these options can be used in conjunction with and withoutmechanical contact between the first and second elements. Contactbetween the movable first and second elements through the yieldableindexing means may in some situations be useful to retard and bettercontrol the velocity rate of the relative movement between the first andsecond elements.

The meat processing equipment according to the invention can also havethe first element include a cavity for accommodating the first magnetand/or the second element may include a cavity for accommodating thesecond magnet. Such cavities are easily formed into first and secondelements of non-magnetic material and also can be easily sealed againstthe ingress of contaminations, in particular bacterial contaminations.In combination with attracting magnets the yieldable arresting means canalso function entirely contactless, which is a further advantage inmaintaining hygienic conditions.

It is further advantageous when in meat processing equipment accordingto the invention the second element includes a further cavity thataccommodates a third permanent magnet forming a pair with the secondmagnet. In particular this is the case when the first and second magnetsare not attracting one another, when the first element does not includea cavity for accommodating the first magnet, or when the second elementdoes not include a cavity for accommodating the second magnet. Whenarresting one repulsive magnet in the first element between a pair ofrepulsive magnets in the second element, a firmer indexing may beobtained that can still function in a contactless manner.

The meat processing equipment according to the invention can also haveone of the first and second magnets being part of a plunger that isarranged for translating movement in a direction perpendicular to thecommon plane and slideably held in a mating cavity in one of the firstand second elements, and wherein the other of the first and secondelements in the respective first or second face is provided with arecess engageable by the plunger. In particular this is the case whenone of the following applies: the first and second magnets are notattracting one another, the first element does not include a cavity foraccommodating the first magnet, or the second element does not include acavity for accommodating the second magnet. In such an embodiment boththe first and second magnets may optionally also be associated with thesecond element, on one side of the common plane. Depending on whetherattractive or repulsive magnetic forces are use to bias the plunger intoengagement with the recess, the extent of frictional engagement may beadapted to requirements. With magnetic attraction friction between theplunger and the first element is operative only in the vicinity of therecess of the first element. With magnetic repulsive forces the plungeris continuously urged toward the first element. This action iscomparable to a helical spring as used in the prior art, but without theintricate surface portions of a helical spring that may result in anadditional contamination hazard.

The meat processing equipment according to the invention may also havethe yieldable arresting means advantageously incorporated in a supportassembly for parts of slaughtered animals. In particular this is thecase when the first and second magnets are not attracting one another,when the first element does not include a cavity for accommodating thefirst magnet, or when the second element does not include a cavity foraccommodating the second magnet. Advantageously the support assembly canbe a hanger for a poultry carcass. In such meat processing equipment thehanger for poultry is arranged for attachment to a conveyor extendingalong a processing path, the poultry hanger further may advantageouslycomprise: a trolley securable to the conveyor; a shackle rotatablysecured with respect to the trolley and be configured to support anarticle; and wherein the yieldable arresting means is embodied as anindexing arrangement associated with the shackle and configured tomaintain the shackle yieldably in at least a first and a second indexedrotational orientation relative to the processing path; the indexingarrangement comprising confronting surfaces rotatable with respect toeach other and having surface features that mate when the shackle is inthe first and the second indexed rotational orientations; and magnetsassociated with the indexing arrangement, the magnets being positionedand oriented to urge the confronting surfaces toward one another throughmagnetic force when the shackle is in the first and the second indexedrotational orientations. Optionally such meat processing equipment mayfurther optionally comprising a turning block associated with theshackle, wherein rotation of the turning block relative to the trolleycauses corresponding rotation of the shackle relative to the trolley. Inthis regard it is optionally advantageous when the indexing arrangementis disposed between the turning block and the trolley.

The meat processing equipment of the invention may alternatively oradditionally have the yieldable arresting means incorporated in asupport assembly for parts of slaughtered animals, being a bone holder.Accordingly the bone holder may then also be rotatably suspended from anoverhead conveyor. Advantageously the bone holder may alternatively oradditionally include a receiving block and a locking arm that isswivelable with respect to the receiving block between an open and aclosed position and is embodied as one of the first and second elementsand wherein the receiving block is then embodied as the other of thefirst and second elements. In such meat processing equipment theswivelable locking arm can be magnetically latched in its closedposition and/or the swivelable locking arm can be magnetically arrestedin its open position.

The latter mentioned specific exemplary applications of arresting meansshould not be regarded as limiting the invention in any way. These aremerely examples of practical embodiments, but various others will beapparent to the skilled person without diverting from the invention asdefined in the appended claims.

Further advantageous aspects of the invention will become clear from theappended description and in reference to the accompanying drawings,which are briefly described as follows:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective illustration of a rotatable articlesupport;

FIG. 2 is a cross section of the exploded perspective illustration ofFIG. 1;

FIG. 3 is a side elevation in ghost view of the article support of FIGS.1 and 2;

FIG. 4 is a rear elevation in ghost view of the article support of FIGS.1, 2 and 3;

FIG. 5 shows a first arrangement of turning pins in relation to a firstoutput position for the article support;

FIG. 6 shows a second arrangement of turning pins in relation to asecond output position of the article support;

FIG. 7 shows a third arrangement of turning pins in relation to a thirdoutput position for the article support;

FIG. 8 shows a fourth arrangement of turning pins in relation to afourth output position for the article support;

FIG. 9 schematically illustrates a first alternative embodiment ofyieldable arresting means that can be used for indexing and latching;

FIG. 10 schematically illustrates a second alternative embodiment ofyieldable arresting means;

FIG. 11 schematically illustrates a third alternative embodiment ofyieldable arresting means;

FIG. 12 schematically illustrates a fourth alternative embodiment ofyieldable arresting means;

FIG. 13 shows a bone holder as a further use of magnetic arresting meansin meat processing equipment;

FIG. 14 shows the bone holder of FIG. 13, but with its locking arm in anopen position; and

FIG. 15 is a perspective exploded view of the bone holder of FIGS. 13and 14.

DETAILED DESCRIPTION

In FIG. 1 an exploded arrangement is shown of a rotatable articlesupport assembly 1. The article support assembly 1 is provided with ashackle 3, which in this example is a so called weighing shackle for thesuspension of animal carcasses, such as fowl or poultry carcasses. Theshackle 3 is rotatably suspended from a base block 5. The base block 5is arranged for movement along an overhead conveyor rail or track (notshown, but conventional). Such conveyor rails or tracks are common inindustrial apparatuses for carrying out a succession of processingsteps. Commonly such conveying tracks are laid out in a continuous loopthat defines a path of conveyance along a plurality of processingstations. Such systems are well known in the meat processing industry,but are also used in other disciplines of industry and manufacture. Inthis regard the base block 5 forms a trolley or carriage that is linkedto similar base blocks of adjacent article support assemblies by trolleybrackets 7 and chains, or the like. The trolley brackets 7 are attachedto the base block 5 by means of bolts 9 and nuts 11. Extending upwardlyfrom shackle 3 is a shaft 13 to which an abutment flange 15 is attachedby means of a first transverse pin 17. The shaft 13 extends upwardlythrough a central bore in the base block 5, which central is enlarged atthe upper end of the base block 5 to form a cavity 19. The cavity 19, asbest seen in FIG. 2, has three bores 21 (only one visible in FIG. 2) foreach receiving a lower magnet 23. The cavity 19 has a groove 25 fornon-rotatably receiving an indexing plunger 27 which has it perimeteradapted to the contour of cavity 19 to inhibit relative rotation but toallow axial movement of the plunger 27.

Not visible in FIGS. 1 and 2, but visible in the ghost views of FIGS. 3and 4, the indexing plunger 27 has bores opening into its bottom surfacefor receiving upper magnets 29. In this example the lower magnets 23 arepositioned with their north poles on top and the upper magnets 29 arepositioned with their north poles facing down. In such an orientation,the lower and upper magnets 23, 29 will repulse one another, so that theindexing plunger 27 carries a number of radial indexing formations 31,which cooperate with complementary indexing formation on a lower face ofa turning gear, or turning block 33. In this example, the indexingformations 31 provide rotational positions that are 90° apart. Theturning block 33 is mounted to the shaft 13 by means of a secondtransverse pin 35. Spacing between transverse bore in the shaft 13 forreceiving the first and second transverse pins 17, 35 is such that thebase block 5 is snugly and rotatably received between the abutmentflange 15 and the turning block 33. Thereby also the indexing plunger 27is held within the cavity 19 of the base block 5 against the repulsiveforces of the confronting lower and upper magnets 23, 29. The magnets23, 29 are preferably identical and sintered rare earth magnets. Suchsintered rare earth magnets may contain neodymium or be ceramic magnetsof ferrous material. Another suitable magnet material may be samariumcobalt. The polarity of the lower and upper magnets 23, 29 should beproperly directed to obtain the repulsive force necessary to bias theindexing formation 31 in engagement with the turning block 33. This canbe with the north poles of confronting magnets facing one another, butmay also be achieved by having the south poles facing one another. Theimportant aspect is that equal poles of confronting magnets are facingone another. The turning block 33 further has diagonal slots 37extending diagonally inwardly from each corner of the substantiallysquare contour of the turning block 33.

In FIGS. 3 and 4 a side and a rear elevation of the assembled articlesupport assembly 1 are illustrated as ghost views. Thereby internalparts like the magnets 23, 29, the indexing plunger 27 and the indexingformations 31 are visible as if the base block 5 and the turning block33 were of transparent material. Also best visible in FIGS. 3 and 4 isthat the turning block 33 has an upper cut-out 39 along one edgeextending between adjacent slots 37, as well as a lower cut-out 41 alonganother edge that is perpendicular to the one edge.

The purpose of the upper and lower cut-outs will now be described inreference to FIGS. 5 to 8. In FIGS. 5 to 8 several output positions areshown for the article support assembly 1, after having passed particularaligning, or turning stations 43A, 43B, 43C, 43D in a direction ofconveyance indicated by arrow 45. The representation of FIGS. 5 to 8 isessentially schematic and structure that is not directly relevant to acorrect understanding of the present disclosure, is omitted for clarity.Also the article support assembly 1 is shown in a simplified form withthe turning block 33 separated in two levels of disks 33A, 33B to bettervisualise the upper and lower cut-outs 39, 41. Each of the turningstations 43A-43D has opposed left and right hand guiding walls 47, 49.Each left hand and right hand guiding wall 47, 49 has a series ofopenings 51 in a upper and a lower row, each consisting of threeopenings 51. Each opening 51 is adapted to selectively receive a turningpin 53. As shown in FIG. 5, three turning pins 53 are successivelyarranged in the upper row of openings 51 of the left hand guiding wall47. Irrespective of the rotational position of the article supportassembly 1 when it enters the turning station 43A, the three successiveturning pins 53 in the upper row will always be sufficient to engage asmany of the diagonal slots 37 as is necessary to bring the upper cut-out39 (in level 33A of the turning block) in a position facing the lefthand guide rail 47, once it has passed all three turning pins 53.

As shown in FIG. 6, three turning pins 53 are now mounted in the upperrow of three opening 51 of the right hand guiding wall 49. This has theeffect that article supported assembly 1 will now leave the turningstation 43B with the upper cut-out 39 facing the right hand guiding wall49. This results in a different position of the shackle 3 than thatachieved with the turning station 43A of FIG. 5.

In FIG. 7 again a different arrangement of turning station 43C is shown.In this variation the three successive turning pins 53 are positioned inthe lower row of opening 51 of the left hand guiding wall 47. The pins53 now engage the diagonal slots 37 at the lower portion 33B of theturning block. Upon passage of the article support assembly 1 throughthe turning station 43C in the direction 45 of conveyance, the lowercut-out 41 will emerge from the turning station 43C, facing the lefthand guide wall 47.

In a further variation according to FIG. 8, the turning station 43D hasthe successive turning pins 53 installed on the lower row of openings 51in the right hand guide wall 49. This results in the lower cut-out 41 ofthe lower portion 33B of the turning block to emerge from the turningstation 43D facing the right hand side wall 49. While one level ofturning pins 53 that are 180° apart, using a second level forpositioning the turning pins and a second cut-out at 90° from the firstcut-out, enables positioning of the article support assembly 1 atpredetermined position at 90°.

Accordingly an article support assembly 1 is disclosed that is adaptedfor movement by a conveyor along a path of conveyance. The articlesupport assembly 1 includes a trolley 5 for engagement by the conveyorand a shackle 3 configured to support an article, and rotatable withrespect to the trolley. A turning block 33 is associated with theshackle 3, and rotation of the turning block with respect to the trolley5 causes corresponding rotation of the shackle relative to the trolley.Yieldable indexing means 23, 27, 29, 31 are operatively arranged betweenthe trolley 5 and the turning block 33 to define at least a first and asecond incremental rotational position for the shackle 3. The yieldableindexing means 23, 27, 29, 31 of the article support assembly 1 arebiased into engagement by magnetic repelling forces. A conveyor systemfor conveying articles along processing stations is adapted to includethe article support assembly 1 and comprises the turning stations 43A,43B, 43C, 43D for giving a predetermined rotational position to theshackle 3 with respect to the trolley 5.

While it has been described in the above example that the indexingplunger 27 and the turning block 33 providing the yieldable indexingmeans are biased into engagement by magnetic repelling forces, it isalternatively also possible to obtain this bias by attracting magneticforces. This effect can be obtained by positioning lower magnet in theindexing plunger 27, and accommodating upper magnets in suitable boresin the turning block 33, but with the confronting lower and uppermagnets then positioned to have their opposite poles facing one another.

FIGS. 9 to 12 illustrate schematically several options of obtainingyieldable arresting means for indexing and latching predeterminedrelative positions between first and second relatively movable elements61, 63. Each of the first and second elements 61, 63 is shown in partialcross section and it is to be understood that the first element 61 canbe spaced from the second element 63 along an imaginary plane 65. Inother words there need not be contact between the first and secondelements 61, 63 when these are moved by relative translation or rotationin parallel to the imaginary plane 65.

In FIG. 9 there is also no contact between the yieldable arresting meansformed by a first magnet 67 in the first element 61 and a second magnet69 in the second element 63. The polarity of the first and secondmagnets 67, 69 is arranged such that their confronting poles attract oneanother. In FIG. 9 this is schematically indicated by “N” for north poleand “S” for south pole.

In the embodiment of FIG. 10 repelling forces are used to obtain apredetermined indexing position between the first and second elements61, 63. To this end the embodiment of FIG. 10 uses a first upper magnet67 and a pair of lower second magnets 71, 73. In this arrangement thepolarities of the magnets are arranged such that these repel oneanother. In this way the upper magnet 67 will be arrested in apredetermined position in between the pair of lower magnets 71, 73. Thearresting means of FIG. 10 may be more suitable for applications inwhich the velocity difference between the first and second elements 61,63 is of such magnitude that arresting the movement with a singleattracting magnet (such as in FIG. 9) may not function reliably.

While the arresting means according to the embodiments of FIGS. 9 and 10are completely contactless, there may also be situations where somefriction is beneficial to control the movement taking place between thefirst and second elements 61, 63. Accordingly is it also possible toachieve magnetic arresting with mechanical contact between the first andsecond elements. FIG. 11 schematically illustrates one example that usesmechanical contact of a plunger element 75 that can telescope in and outfrom a mating cavity 77 in the second element 63. The first element 61is provided with a recess 79, into which the plunger 75 can engage toarrest the first and second elements 61, 63 in a predetermined position.The plunger includes a plunger magnet 81, which is attracted by an uppermagnet 67 in the first element 61. In this arrangement the plunger 75 isonly urged toward the first element 61, when in the vicinity of therecess 79 which defines the indexing position. Friction will thus belimited to the direct area of engagement between the plunger 75 and therecess 79. The arrangement of FIG. 11 corresponds to the alternativethat is mentioned above for the rotatable poultry meat hanger 1 of FIGS.1 to 4.

Another embodiment that uses mechanical contact between a plunger 75 anda first element 61 is shown in FIG. 12. The plunger 75 is again providedwith a plunger magnet 81 and telescopable with respect to a matingcavity 77 as in the embodiment of FIG. 12. In contrast the first element61 does not have a magnet but a further magnet 83 is now positionedbelow the cavity 77. The polarities of the uppermost plunger magnet 81and the lowermost further magnet 83 are such that these are repellingone another. The repelling force between the magnets 81, 83 now urgesthe plunger 75 continually against the first element 61. This may resultin a controlled amount of friction between the first and second elements61, 63 that keeps the speed differences between the first and secondelements 61, 63 under control, also when the plunger is not in thevicinity of the recess 79 in the first element 61. The arrangement ofFIG. 12 corresponds to the yieldable indexing means 23, 27, 29, 31 ofthe hanger 1 of FIG. 1-4.

It should be noticed in respect to the various embodiments in accordancewith FIGS. 9, 10, 11 and 12 that the magnets 67, 69, 71, 73, 81, 83 areencased in a non-magnetic material, such as plastic.

Encasing the magnets in the contactless arrangements of FIGS. 9 and 10is particularly favourable for meat processing lines. As there is anissue with bacterial contamination, wherever the traditional indexingand arresting means create cavities, the arrangement of FIGS. 9 and 10creates favourable circumstances to prevent bacterial contamination andto promote hygiene.

FIGS. 13 to 15 show yet another use of magnetic arresting means in meatprocessing equipment. Shown is a bone holder 101 that can be part of anoverhead conveyor from which it is suspended by a trolley 103 connectedto a trolley bracket, or shackle connector 107. Although for clarityonly one trolley 103 is shown it should be understood that a similartrolley will be connected to the opposite trolley bracket 107. Bothtrolley brackets 107 are connected to a base block 105 that may besomewhat similar to the base block of the embodiment of FIGS. 1 to 4,including turning and indexing means for rotatably mounting a receivingblock 109. The trolleys 103 will be connected to other trolleys by meansof a chain 111, of which only a portion is shown. The receiving block ofthe bone holder 101 has a bifurcated receiving hook 113 at its lowerend. A locking arm 115 is swivably mounted to the receiving block 109 tosecure a bone knuckle engaged in the receiving slot 117. FIG. 14 showsthe bone holder 101 with the swivable locking arm 115 in an openposition, ready to receive an animal bone part. As can be seen in FIGS.13 and 14 the locking arm 115 when closed is engaged against an abutmentmember 119 and in open position is arrested by magnets 121, of whichonly an outer one is visible. The arrangement, however, may correspondto either the FIG. 9 or FIG. 10 variant. It will further be seen in theexploded view of FIG. 15 that the receiving block 109 has mountedtherein outer magnets 121 to confront inner magnets 123 on the swivablelocking arm 115. The abutment member 119 has a first pair of latchmagnets 125 mounted therein, while the locking arm 115 has a furthersecond pair of latch magnets 127 mounted therein. The locking arm 115 ismounted for pivotal movement with respect to the receiving block 109 bymeans of a first pivot shaft 129 that is inserted through correspondingopenings 131, 133 in the receiving block 109 and locking arm 115. Thepivot shaft 129 is non-rotatably secured to the locking arm 115 by atransverse locking pin 135. Thus the locking arm 115 has only two stablepositions, a first one when open and arrested by the outer and innermagnets 121, 123, and a second one when engaged against the abutmentmember 119 by a force generated by the attracting first and second pairof magnets 125, 127. As further seen in FIGS. 13 to 15 the first pivotshaft 129 on an exposed end is provided with an operating arm 137. Theoperating arm 137 is used to swivel the locking arm 115 from its open toits closed position and vice-versa. As bones to be held by the receivingblock 109 of the bone holder 101 come in various sizes, the abutmentmember 119 is adjustably mounted about a second pivot shaft 139 thatengages through aligned openings 141, 143 in the receiving block 109 andthe abutment member 119. The second pivot shaft 139 is held in positionby suitable screw fasteners 145 and optional further hardware, such aswashers. For adjustment the abutment member 119 cooperates with a screwadjuster, generally indicated by reference numeral 147. Further it isshown that the bifurcated receiving hook 113 is detachably mounted byconventional fasteners 149, to be exchanged by differently sized units.This feature may further extend the range of animal bones that can beheld by the device. It is also of advantage that the attracting force ofthe confronting pairs of latching magnets 125, 127 will also accommodateslight variation in size of bones, which may still occur, in spite of aparticular adjustment made to the abutment member 119.

It is thus believed that the operation and construction of the presentinvention will be apparent from the foregoing description and drawingsappended thereto. It will be clear to the skilled person that theinvention is not limited to any embodiment herein described and thatmodifications are possible which should be considered within the scopeof the appended claims. Also kinematic inversions are consideredinherently disclosed and to be within the scope of the invention. In theclaims, any reference signs shall not be construed as limiting theclaim. The term ‘comprising’ and ‘including’ when used in thisdescription or the appended claims should not be construed in anexclusive or exhaustive sense but rather in an inclusive sense. Thus theexpression ‘comprising’ as used herein does not exclude the presence ofother elements or steps in addition to those listed in any claim.Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to‘only one’, but instead are used to mean ‘at least one’, and do notexclude a plurality. Features that are not specifically or explicitlydescribed or claimed may be additionally included in the structure ofthe invention within its scope. Expressions such as: “means for . . . ”should be read as: “component configured for . . . ” or “memberconstructed to . . . ” and should be construed to include equivalentsfor the structures disclosed. The use of expressions like: “critical”,“preferred”, “especially preferred” etc. is not intended to limit theinvention. Additions, deletions, and modifications within the purview ofthe skilled person may generally be made without departing from thespirit and scope of the invention, as is determined by the claims.

1.-18. (canceled)
 19. An apparatus for holding an animal part at one endof a bone of the animal part as the animal part is conveyed along aprocessing path, the apparatus comprising: a bone holder assemblyconfigured to be suspended from and conveyed along the processing pathby an overhead conveyor, the bone holder assembly comprising a receivingblock at a lower end of the assembly; a receiving hook mounted to thereceiving block and defining an open receiving slot sized to receive abone of an animal part; a locking arm movably mounted to the receivingblock, the locking arm being selectively movable between a closedposition wherein a portion of the locking arm is located within thereceiving slot for securing the bone of an animal part in the receivingslot and an open position displaced from the receiving slot to allow thebone of an animal part to be inserted into or removed from the receivingslot; an operating arm coupled to the locking arm, the operating armbeing operable to move the locking arm between the closed position andthe open position; at least one first magnet associated with the lockingarm; at least one second magnet associated with the receiving block; thefirst and second magnets being positioned to align substantially whenthe locking arm is moved to the open position to maintain the lockingarm yieldably in the open position through magnetic interaction betweenthe first and second magnets.
 20. An apparatus for holding an animalpart as claimed in claim 19 wherein the at least one first magnet isembedded in the locking arm.
 21. An apparatus for holding an animal partas claimed in claim 19 wherein the at least one second magnet isembedded in the receiving block.
 22. An apparatus for holding an animalpart as claimed in claim 19 wherein the magnetic interaction comprisesmagnetic attraction.
 23. An apparatus for holding an animal part asclaimed in claim 19 wherein the magnetic interaction comprises magneticrepulsion.
 24. An apparatus for holding an animal part as claimed inclaim 19 wherein the locking arm comprises a hooked portion that engagesthe bone of an animal part in the receiving slot when the locking arm isin the closed position.
 25. An apparatus for holding an animal part asclaimed in claim 19 wherein the at least one first magnet comprises apair of first magnets and the at least one second magnet comprises apair of second magnets.
 26. An apparatus for holding an animal part asclaimed in claim 19 further comprising at least one third magnetassociated with the locking arm and at least one fourth magnet, thethird and fourth magnets being positioned to align substantially whenthe locking arm is moved to the closed position to maintain the lockingarm yieldably in the closed position through magnetic interactionbetween the third and fourth magnets.
 21. An apparatus for holding ananimal part as claimed in claim 26 further comprising an abutment memberassociated with the receiving block and positioned to confront thelocking arm when the locking arm is in the closed position, the at leastone fourth magnet being associated with the abutment member.
 22. Anapparatus for holding an animal part as claimed in claim 21 furthercomprising an adjustment member configured to adjust the location of theabutment member to accommodate different closed positions of the lockingmember associated with animal parts of different sizes.
 23. An apparatusfor holding an animal part as claimed in claim 21 wherein the at leastone third magnet comprises a pair of third magnets and the at least onefourth magnet comprises a pair of fourth magnets.
 24. Meat processingequipment comprising: a support assembly for holding parts ofslaughtered animals, the support assembly comprising a bone holder; thebone holder including a bifurcated receiving hook defining a receivingslot sized to receive a portion of the parts of slaughtered animals sothat the parts are suspended from the receiving hook; a locking arm onthe support assembly and being movable between a closed position whereina portion of the locking arm extends partially into the receiving slotto secure parts of slaughtered animals in the receiving slot and an openposition displaced from the receiving slot to allow parts of slaughteredanimals to be inserted into and removed from the receiving slot; thelocking arm having a first face and the bone holder having a secondface, the first face being disposed adjacent the second face when thelocking arm is in the closed position; and at least one first magnetassociated with the first face and at least one second magnet associatedwith the second face, the first and second magnets being positioned tourge the locking arm yieldably toward its closed position throughmagnetic interaction when the locking arm is moved from the openposition to the closed position.
 25. Meat processing equipment asclaimed in claim 24 wherein the magnetic interaction comprises magneticattraction.
 26. Meat processing equipment as claimed in claim 25 whereinthe first face confronts the second face when the locking arm is in theclosed position.
 27. Meat processing equipment as claimed in claim 24further comprising at least one third magnet associated with the lockingarm and at least one fourth magnet associated with the support assembly,the third magnet and the fourth magnet being arranged to hold thelocking arm yieldably in its open position through magnetic interactionwhen the locking arm is moved to the open position.
 28. Meat processingequipment as claimed in claim 24 wherein the locking arm is pivotallymounted to the support assembly and is arranged to pivot between theopen position and the closed position.
 29. Meat processing equipment asclaimed in claim 28 further comprising an operating arm operativelycoupled to the locking arm for selective pivotal movement of the lockingarm between the open position and the closed position.
 30. Meatprocessing equipment as claimed in claim 24 further comprising anabutment member on the support assembly, the at least one second magnetbeing associated with the abutment member.
 31. Meat processing equipmentas claimed in claim 30 further comprising an adjuster configured forselective adjustment of the position of the abutment member toaccommodate the holding by the locking arm of animal parts of differentsizes within the receiving slot.